Moshe Bar Kepha, as a churchman, exegete and apologist, lived in the time and place of the most troubled center of the Abbasid Empire, witnessing the consequences of its policies upon the Christian communities. The most daring policy was the Islamization policy of Caliph al-Mutawakkil (d. 861), under which Christianity was not merely assailed as a false faith, but also as a social evil. In addition to paying Jizyah, this caliph further humiliated the Christians by imposing on them harsher rules which came to be known as "ʿUmar Conditions."It was in the context of enduring the Islamization policy and in the context of open and receptive relationships among Christians of different traditions that Moshe Bar Kepha ministered, taught, and wrote his Commentary on the Gospel of Luke. In fact, he produced a masterpiece of an inclusive (ecumenical) theological approach, and with apologetic tendency responding to Muslims.Through examples from his Commentary, I will illuminate Moshe Bar Kepha's position on various theological topics. He presented them in a harmonious way, stressing the essential unity among all Christians. At the same time, by means of instructing his Christian community, Moshe Bar Kepha responded to Muslims' challenge to the Christian faith.